A terminal connector to be connected to an end of an electric wire is conventionally known as described in Patent Document 1. The terminal connector includes a crimping portion made by pressing a metal plate. The crimping portion is crimped onto a core wire exposed at the end of the electric wire.
If an oxide layer is formed on the core wire, the oxide layer intervenes between the core wire and the crimping portion. This may cause increase in contact resistance between the core wire and the crimping portion.
Therefore, in the conventional art, grooves (serrations) are formed in the inner side (the core-wire side) of the crimping portion. The grooves continuously extend in a direction crossing the extending direction of the electric wire. The plurality of grooves are spaced in the extending direction of the electric wire. The grooves are formed by press molding a metal plate with a die.
When the crimping portion is crimped onto the core wire of the electric wire, the crimping portion presses the core wire so that the core wire plastically deforms in the extending direction of the wire. Then, opening edges of the grooves come into scraping contact with the oxide layer on the surface of the core wire, thereby removing the oxide layer. Then, the new surface of the core wire and the crimping portion come into contact with each other. This can reduce the contact resistance between the electric wire and the terminal connector.